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|
%{
/* first section */
%}
%%
%{
/* second section */
%}
S : /* empty */ { printf("S -> epsilon\n"); }
| '(' S ')' S { printf("S -> ( S ) S\n"); }
%ifdef ABC
/* see how preprocessor can be used */
| '*' { printf("S -> *\n"); }
%endif
;
%%
#include <stdio.h>
main() {
printf("yyparse() = %d\n",yyparse());
}
yylex() {
int ch;
do { ch = getchar(); } while (ch == ' ' || ch == '\n' || ch == '\t');
if (ch == EOF) return 0;
return ch;
}
yyerror(s) char*s; {
printf("%s\n",s);
}
|
